Two new ent-labdane diterpenoid glycosides were isolated from the aerial parts of Andrographis paniculata. Their structures were elucidated as 3-O-β-d-glucosyl-14-deoxyandrographiside (1) and ...3-O-β-d-glucosyl-14-deoxy-11,12-didehydroandrographiside (2) by means of 1D and 2D NMR spectral and chemical methods.
A study of the cross-linking immobilization of β-galactosidase from
Kluyveromyces lactis on graphite surfaces is reported here. The cross-linking reagent was glutaraldehyde. Thermal deactivation of ...the immobilized enzyme at the temperatures from 35 to 55°C was investigated, and the deactivation rate was found to follow the Arrhenius law with the activation energy of about 200
kJ
mol
−1 for the deactivation of the immobilized enzyme. The temperature-activity curves are similar for both the free and immobilized enzyme. However, the maximum activity of the immobilized enzyme was shifted up from 40°C to 50°C compared with that of the free enzyme. The pH for the maximum activity of the immobilized enzyme to occur has been found to increase by 1.1 to 7.7
U compared with the free enzyme. Lactose hydrolysis in a skim milk using the immobilized enzyme has also been investigated in a continuous enzymatic reactor. The related mechanisms of the hydrolysis process are discussed.
Hematoporphyrin monomethyl ether (HMME) is a novel and promising porphyrin-related photosensitizer for photodynamic therapy (PDT). HMME-PDT-induced cell death and its mechanisms were investigated in ...HeLa cells. We demonstrated that HMME-PDT could induce cell death through both necrosis and apoptosis. Sodium azide (the singlet oxygen quencher) or
d-mannitol (the hydroxyl radical scavenger) could protect HeLa cells from the apoptosis and necrosis induced by HMME-PDT, showing that reactive oxygen species (ROS), such as singlet oxygen and hydroxyl radical, played a decisive role in HMME-PDT-induced HeLa cells death. Sodium azide or
d-mannitol also inhibited HMME-PDT-mediated Ca
2+
i elevation. Cytochrome C (Cyto C) release from mitochondria into cytosol and Caspase-3 activation after HMME-PDT were inhibited by BAPTA/AM (an intracellular calcium chelator). These results demonstrated that ROS generated in HeLa cells by HMME-PDT-induced apoptosis may be through Ca
2+
i elevation which mediates Cyto C release and Caspase-3 activition and initiates the subsequent late stages of apoptosis.
A novel and simple optical chemsensor concept based on cladding etched Bragg gratings UV-inscribed in D-fibre is reported. The sensitisation process of the Bragg structure to the refractive index of ...surrounding-medium under HF-etching has been investigated. Two etched devices were used to measure the concentrations of sugar solution, giving sensitivity as high as 0.02 nm/%.
Despite the significance of cigarette smoke for carcinogenesis, the molecular mechanisms that lead to increased susceptibility of human cancers are not well-understood. In our present study, the ...oncogenic transforming effects of cigarette smoke condensate (CSC) were examined using papillomavirus-immortalized human bronchial epithelial cells (BEP2D). Growth kinetics, saturation density, resistance to serum-induced terminal differentiation, anchorage-independent growth and tumorigenicity in nude mice were used to investigate the various stages of transformation in BEP2D cells. Illumina microarray platforms were used to explore the CSC-induced alteration of global mRNA expression profiles of the earlier period and the advanced stage of CSC-treated BEP2D cells. We showed here that a series of sequential steps arose among CSC-treated immortalized human bronchial epithelial cells, including altered growth kinetics, resistance to serum-induced terminal differentiation, and anchorage-independence growth. In the earlier period of CSC treatment, 265 genes were down-regulated and 63 genes were up-regulated, respectively, and in the advanced stage of CSC treatment, 313 genes were down-regulated and 145 genes were up-regulated, respectively. Notably, among those genes, the expression of some of imprinted genes such as IGF2, NDN, H19 and MEG3 were all silenced or down-regulated in CSC-treated cells. These genes reactivated after 5
μM 5-aza-2-deoxycytidine (5-aza-dC) treatment. These results demonstrated that long-term treatment of human bronchial epithelial cells with CSC may adversely affect their genetic and epigenetic integrity and lead to further transformation.
There is recently great interest in haplotype block structure and haplotype tagging SNPs (htSNPs) in the human genome for its implication on htSNPs-based association mapping strategy for complex ...disease. Different definitions have been used to characterize the haplotype block structure in the human genome, and several different performance criteria and algorithms have been suggested on htSNPs selection.
A heuristic algorithm, generalized branch-and-bound algorithm, is applied to the searching of minimal set of haplotype tagging SNPs (htSNPs) according to different htSNPs performance criteria. We develop a software htSNPer1.0 to implement the algorithm, and integrate three htSNPs performance criteria and four haplotype block definitions for haplotype block partitioning. It is a software with powerful Graphical User Interface (GUI), which can be used to characterize the haplotype block structure and select htSNPs in the candidate gene or interested genomic regions. It can find the global optimization with only a fraction of the computing time consumed by exhaustive searching algorithm.
htSNPer1.0 allows molecular geneticists to perform haplotype block analysis and htSNPs selection using different definitions and performance criteria. The software is a powerful tool for those focusing on association mapping based on strategy of haplotype block and htSNPs.
Li4Ti5O12 based spinel-framework structures are of great interest as negative electrode materials for lithium-ion batteries. We describe here the first synthesis of nano-scale Li4Ti5O12 material ...using sol–gel method, by which excellent phase purity and good stoichiometric inorganic oxides were obtained. According to the X-ray diffraction and transmission electron microscopy analysis, uniformly distributed Li4Ti5O12 particles with grain sizes of 100nm were synthesized. Lithium cells, consisting of Li4Ti5O12 cathodes and lithium anodes, showed the initial capacity of 272mAhg−1 in the range of 1.0–2.5V. Furthermore, the crystalline structure of Li4Ti5O12 didn’t transform during the lithium intercalation and deintercalation process.
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